[Erlotinib plus Bevacizumab Therapy for Postoperative Recurrence of Adenosquamous Cell Carcinoma Harboring EGFR Mutation-A Case Report].

A 59-year-old man clinically diagnosed with primary lung cancer underwent left lower lobectomy and lymph node dissection( ND2a-2). The postoperative pathological stage was ⅠB(pT2aN0M0), and the lesion was positive for epidermal growth factor receptor(EGFR)exon 21 L858R mutation. Thirty months after surgery, the patient developed pleural dissemination and effusion in the left pleural cavity. Carboplatin(AUC=6, day 1, every 3 weeks)and nab-paclitaxel(100 mg/m2, day 1 and day 8, every 3 weeks)were administered as first-line therapy. Progressive disease was evident 10 months after 4 courses of first-line therapy. Pembrolizumab(200 mg, day 1, every 3 weeks)was then administered as second-line therapy. After 7 months(9 courses of therapy), the lung cancer had metastasized to the left third intercostal muscle, and the pleural nodules regrew. The former lesion was treated with radiotherapy owing to the development of pain in the chest. Erlotinib (150 mg once daily)and bevacizumab(15 mg/kg, day 1, every 3 weeks)were initiated as third-line therapy, resulting in complete response at 14 months(67 months after surgery, 37 months after postoperative recurrence). The prognosis of patients with EGFR-positive pulmonary adenosquamous carcinoma and undergoing treatment with EGFR-tyrosine kinase inhibitors(TKI)is reportedly poor. Herein, we report a rare case of adenosquamous carcinoma with EGFR mutation presenting complete response following treatment with EGFR-TKI.